1. Field of Invention
The present invention relates to a method of adjusting selected window size of an image object, and more particularly to a method used in consecutive image frames having a target object for automatically adjusting selected window size of the image object according to size variation of the target object in the image frames.
2. Related Art
Nowadays when the multimedia information is developed, in order to recognize the content or object in the video, techniques for detecting and tracking the object are commonly used. For example, the detection on human faces or the enclosing on car number-plates in the security system require for the correct enclosing of the target object.
The conventional method for capturing the target object in the video includes using an image selected window having a fixed size to enclose the target object, and the size of the selected window is optimally closest to the size of the target object. Generally speaking, the target object in various frames usually changes in size as time passes. For example, the close-up lens or far-away lens may change the displaying size of the target object in the frame. If the selected window having a fixed size is used to enclose the target object, when the size of the target object is larger or smaller than the selected window, the feature values of the target object captured by the selected window may be different in the subsequent application, thus causing an error in the calculation result.
Therefore, a variable selected window is also proposed to be applied on a varying target object. If the selected window is adjusted to the corresponding size of the target object in each frame, the calculation load of a calculation unit may be increased, and the size of the selected window may be varied severely. For example, in a common video, the variation of target object may often be incorrectly determined by the computer due to the influence of light or background, such that the enclosing range of the selected window may be changed significantly.